Press Release

Scientists at the Centers for Disease Control and Prevention have
successfully reconstructed the influenza virus strain responsible for the
1918 pandemic, a project that greatly advances preparedness efforts for the
next pandemic.

“This groundbreaking research helps unlock the mystery of the 1918 flu
pandemic and is critically important in our efforts to prepare for pandemic
influenza,” said CDC Director Dr. Julie Gerberding. “We need to know much
more about pandemic influenza viruses. Research such as this helps us
understand what makes some influenza viruses more harmful than others. It
also provides us information that may help us identify, early on, influenza
viruses that could cause a pandemic.”

The work, done in collaboration with Mount Sinai School of Medicine, the
Armed Forces Institute of Pathology and Southeast Poultry Research
Laboratory, determined the set of genes in the 1918 virus that made it so
harmful. Prior to this study, which is published in the Oct. 7 issue of
Science, flu experts had little knowledge of what made the 1918 pandemic
so much more deadly than the 1957 and 1968 pandemics. This week’s issue of
Nature also includes a related article entitled “Characterization of the
1918 influenza virus polymerase genes” which describes the final three gene
sequences of the 1918 influenza virus. The work reported in the Nature
article was done by scientists at the Armed Forces Institute of Pathology.

The 1918 pandemic killed an estimated 20-50 million people worldwide,
including 675,000 in the United States. The pandemic’s most striking feature
was its unusually high death rate among otherwise healthy people aged 15-34.
During normal seasonal flu outbreaks, severe complications and death are most
common among the elderly and young children.

Influenza pandemics occur when a new strain emerges to which people have
little or no immunity. Most experts believe another pandemic will occur, but
it is impossible to predict which strain will emerge as the next pandemic
strain, when it will occur or how severe it will be.

“By identifying the characteristics that made the 1918 influenza virus so
harmful, we have information that will help us develop new vaccines and
treatments,” said Dr. Terrence Tumpey, the CDC senior microbiologist who
recreated the virus. “Influenza viruses are constantly evolving, and that
means our science needs to evolve if we want to protect as many people as
possible from pandemic influenza.”

In reconstructing the 1918 influenza virus, researchers learned which
genes were responsible for making the virus so harmful. This is an important
advance for preparedness efforts because knowing which genes are responsible
for causing severe illness helps scientists develop new drugs and vaccines
(e.g., they can focus their research on those genes).

CDC employed stringent biosafety and biosecurity precautions during
research on the 1918 influenza virus. The work was done in a high containment
Biosafety Level 3 lab with enhancements that include special provisions to
protect both laboratory workers and the public from exposure to the virus.
Currently available antiviral drugs have been shown to be effective against
influenza viruses similar to the 1918 influenza virus.

All laboratory work was conducted at CDC. The work was supported in part
with funding from the U.S. Department of Agriculture and the National
Institutes of Health.

To evaluate the benefits of publishing the information contained in these
manuscripts and any potential threat from its possible deliberate misuse,
both manuscripts were reviewed by the National Science Advisory Board on
Biosecurity (NSABB). The NSABB advises the federal government on strategies
for the conduct and communication of research that might yield information or
technologies that could be misused to threaten public health or national
security. The Board was unanimous in its determination that it was critically
important to make these findings available to the scientific community at
large to not only validate their significance, but also permit further
research on the development of diagnostic tests, treatments, and preventative
measures.